Breast cancer is the number one cause of cancer in women in the U.S. It has been established that mammography is the most effective way to screen for the disease. It has been also been established that current state-of-the-art mammographic techniques are far from optimal and are degraded by film noise, limited film contrast and exposure latitude, and inefficient scatter control. it is possible that by combining digital storage phosphor technology, highly absorbing image receptor technology, improved beam qualities, and dose efficient scatter control that the limitations of conventional techniques can be eliminated and the dose efficiency and contrast resolution of mammography can be improved. An objective of this research is to develop and evaluate a scatter free and otherwise optimal single energy digital mammographic unit capable of achieving significantly better images at conventional dose levels or comparable images at 1/3 the dose. Even with improved image quality, visualization of subtle microcalcifications which are crucial to the detection of small early cancers is often obscured by overlying and underlying fat and soft tissue structures. To address this inherent problem, we propose to develop and evaluate a dual energy mammographic unit. To accomplish this, a dual energy cassette consisting of a low atomic number storage phosphor imaging plate (SrF1Br), a copper filter and a high atomic number imaging plate (BaF1Br) sandwich will be used. Our preliminary analysis indicates that a dual energy cassette can achieve good energy separation between the low and high energy images and be able to achieve a good calcium image as well as an excellent single energy (front imaging plate) image at conventional grid screen-film dose levels. Such an approach also eliminates patient misregistration and kYp switching problems. To evaluate the efficacy of the dual energy cassette a clinical trial is proposed. It is anticipated that dual energy mammography will be able to detect cancer earlier than conventional techniques, especially in women with dense breasts who are imaged poorly at this time. The advantages of the earlier detection of breast cancer are well documented.